To stop or disable the GNOME GUI (also known as "X.org") on an Ubuntu Linux machine, you can use the systemctl command to stop the display manager service and prevent it from starting automatically on boot.
To stop the display manager service, use the systemctl command with the stop option. For example:
# systemctl stop gdm:ecruoSwww.lautturi.com
To prevent the display manager service from starting automatically on boot, use the systemctl command with the disable option. For example:
# systemctl disable gdm
It's important to note that stopping or disabling the display manager service will prevent the GNOME GUI from starting automatically on boot. However, it will not remove the GNOME packages or any other dependencies that may be required to run the GUI.
If you want to completely remove the GNOME GUI and all of its dependencies, you can use the apt-get command to uninstall the GNOME packages. For example:
# apt-get remove gnome-core
This will remove the GNOME GUI and all of its dependencies, but it will not remove any configuration files or user data.
It's also important to note that there are many other display managers available for Ubuntu Linux, and the steps to stop or disable the GUI may vary depending on the display manager in use. Consult the documentation and online resources for more information on how to stop or disable the GUI on an Ubuntu Linux machine.